Arteriovenous Reversal Research Articles

Revascularization of Severely Ischemic Limbs by Staged Arteriovenous Reversal.

Purpose: To apply staged arteriovenous reversal in the treatment of extensive and diffuse arterial occlusive disease of the limb. To avoid amputation of the limb or to limit it to necrosed segments.Methods: Exactly 138 patients (a total of 153 severely ischemic limbs) were applied staged arteriovenous reversal (AVR) from January 1984 to December 1995. Generic-specific involvement totaled 106 men and 32 women. Their ages ranged from 24 to 71, averaging 48.7 years. The duration of symptoms ranged from 15 days to 17 years. A total of 112 patients were diagnosed as having Buerger's disease, and 25 had arteriosclerosis. In one patient, the popliteal artery was completely obstructed by acute emboli of atheromatous plaques. Three patients with Buerger's disease had not benefited from lumbar sympathectomy or partial adrenalectomy done several years ago. According to different levels of extensive and diffuse arterial occlusion, arteriovenous reversal was formed at three different sites: (1) high-deep reversal, produced between the external iliac, common femoral, or superficial femoral artery and the superficial femoral vein; (2) low-deep reversal between the distal popliteal artery and tibioperoneal venous trunk; (3) superficial reversal, established between the distal popliteal artery and distal portion of the long saphenous vein.Results: Until June 1996, a total of 132 patients were followed up for 0.5-12 years, averaging 6.5 years. The postoperative results of all limbs except 12 in this series are excellent or good. Cardiac dysfunction does not occur, nor does the marked elevation of venous pressure of the limb.Conclusion: We consider that if the deep venous trunks are patent, the limbs with extensive arterial occlusion are indicated for staged AVR if severe ischemia is present and all other therapeutic methods have failed. Even with necrotic limbs, this operation may lower the level of amputation. The authors suggest that staged arteriovenous reversal is a new and effective approach in the treatment of extensive arterial occlusive disease of the limb.

Disappointing Results of Staged Arteriovenous Reversal (AVR) in Severely Ischemic Extremity

Between 1991 and 1995 the authors performed the arteriovenous fistula (AVF) procedure, which forms the first stage of staged arteriovenous reversal (AVR), in 6 patients (4 with Buerger's disease, 2 with atherosclerosis obliterans) with lower extremity arterial occlusive disease. The patients were all men with a mean age of forty-one years. The clinical indications for revascularization included rest pain and nonhealing ischemic ulcer. The results were disappointing: 4 patients with patent fistulas underwent major amputation, and 2 with occluded fistulas underwent toe amputation.

Arteriovenous reversal for limb salvage in unreconstructible upper extremity arterial occlusive disease

Purpose: Peripheral vascular disease of the upper extremity as a result of atherosclerotic disease or systemic vascular disorders presents a difficult management problem to the vascular surgeon. When extensive distal disease is present bypass procedures with standard arterial reconstruction techniques may not be possible. The use of retrograde perfusion to deliver oxygenated blood to the capillary bed by means of a normal venous system is not new. Flow reversal has been attempted in the myocardial, cerebral, and distal extremity circulations. Arteriovenous reversal (AVR) has been described for limb salvage in patients with upper extremity ischemia, with variable results.Methods: We performed six AVR procedures on five patients with diffuse distal arterial disease and limb-threatening upper extremity ischemia. Two patients had insulin-dependent diabetes, one had systemic lupus erythematosus (two extremities), one had rheumatoid arthritis with vasculitis, and the remaining patient had CRST (calcinosis, Raynaud's disease, sclerodactyly, telangiectasia) syndrome. The two patients with diabetes had systemic manifestations of atherosclerotic vascular disease and lower extremity ischemia; the remaining three patients had no evidence of atherosclerosis. In all patients the AVR was performed at the most distal site of nondiseased artery.Results: Limb salvage was obtained in all cases; one patient had a healed minor digital amputation, and another patient had a healed major amputation. Clinical improvement with resolution of pain was achieved in five of six cases. The remaining patient had a significant diabetic neuropathy that was believed to contribute to her persistent pain.Conclusions: In patients with severe upper extremity ischemia not amenable to standard revascularization techniques, AVR should be considered to provide limb salvage and maximize hand function.

Revascularization of Severely Ischemic Limbs by Staged Arteriovenous Reversal

Having succeeded in salvaging severely ischemic canine hindlimbs by staged arteriovenous reversal, the authors then successfully treated, from January, 1984, to June, 1986, 33 patients with a total of 39 lower extremities by this approach, except for 1 limb. According to the different levels of the extensive and diffuse arterial occlusion, the arteriovenous reversal was formed on three different sites: (1) high-deep reversal, produced between the external iliac, com mon femoral, or superficial femoral artery and the superficial femoral vein; (2) low-deep reversal, made between the distal popliteal artery and the tibiopero neal venous trunk; and (3) superficial reversal, established between the distal popliteal artery and the distal portion of the long saphenous vein. As of April, 1988, these limbs have been followed up for twenty-three to fifty-five months. Except for 1, the postoperative results of the patients in this series are excellent or good. The authors suggest that the staged arteriovenous reversal is a new and ef fective approach in the treatment of extensive arterial occlusive disease of the limb.

Anatomic and Histologic Studies on the Valves of the Venous System in Lower Extremities

Anatomic and histologic studies of vein valves were made on 50 adult cadav ers (100 lower extremities). In the deep and superficial venous trunks, big valves were found mostly with two cuspids. At the inlets of their branches, small valves monocuspid in shape were commonly found. There was no valve in the common iliac vein, and the percentages of the other veins containing valves were: external iliac 42%, common femoral 51%, deep femoral 88%, superficial femoral 100%, popliteal 93%, tibioperoneal trunk 26%, and all the deep veins in the lower leg, including tibial and peroneal 100%. The valves in the deep venous trunk are much stronger than those in the long saphenous vein. They can resist a retrograde pressure of 180 to 420 and 100 to 260 mmHg respectively. The clinical value of this study concerning the staged arteriovenous reversal in the treatment of severely ischemic limbs and the etiology of the primary incompetence of the deep veins of the lower extremity are discussed.

A demonstration of vascular proliferation in response to arteriovenous reversal in the ischemic canine hind limb

Patients with diffuse peripheral vascular disease, resulting in inadequate arteriographic runoff, and/or multiple failed bypasses almost inevitably face amputation. We have previously used an arteriovenous reversal (AVR) procedure at the popliteal level to salvage severely ischemic canine hind limbs. This procedure is followed by the development of an intense network of new vessels in the proximity of the arteriovenous anastomosis. The present study was designed to define the nature of these vessels and their role in providing nutrient perfusion to the limb. Using an established model to create severe limb ischemia, AVR was performed in 24 dogs. Tissue perfusion and neovascularization were assessed by angiography, transcutaneous oximetry (Tc pO 2), tritiated thymidine uptake combined with autoradiography, and histologic capillary density measurements. Angiography revealed the intense vascular network in the region of the anastomosis by postoperative Day 22 in all dogs. TC pO 2 on Day 1 was indicative of severe ischemia in the operated calf compared to controls (12 vs 80 mm Hg, P < 0.01) but returned to normal by Day 22 (81 vs 76 mm Hg). A progressive, significant increase in tritiated thymidine uptake was seen by Day 22 (0.36 vs 0.27 μCi/g, P = 0.005); on autoradiography 95% of these labeled nuclei in the operated limbs were in endothelial cells compared to only 5% in the control limbs. Finally, capillary density studies of the calf muscles showed a substantial increase in the operated limbs (mean, 1011 vs 605 cap/mm 2, P = 0.0004). These studies suggest that the dramatic increase in vascularity observed angiographically following AVR in a severely ischemic limb consists primarily of a rapidly expanding capillary network. That this network of new vessels provides nutritive flow to the limb is confirmed by the progressive increase in tissue oxygenation and absence of tissue necrosis compared with nonrevascularized limbs.

Revascularization of the ischemic canine hindlimb by arteriovenous reversal.

Arteriovenous reversal (AVR) for revascularization of ischemic tissues has previously failed to meet theoretical, experimental, and clinical expectations despite recurrent trials. The efficacy of a new staged approach to AVR was tested against a canine ischemic limb preparation in which global ligation of ipsilateral collaterals inevitably led to limb gangrene. In 12 animals the complications of direct, single-stage end-to-end femoral AVR, inevitably accompanied by the development of extreme edema, were demonstrated. However, when the ischemic preparation was accompanied by a staged AVR, in which an initial end-artery-to-side-vein arteriovenous fistula was converted 1 week later to AVR by ligation of the central venous limb, 20 of 20 animals survived, and 19 of 20 were ambulatory long-term survivors with only mild edema. Serial angiograms at 1 week, 1 month, and 4 months demonstrated patency rates of 100, 84, and 63%, respectively. Histologic examination of animals electively killed from 4 to 24 months showed normal skeletal muscle histology, venous intimal thickening, and mild edema. In the acutely ischemic canine hind limb, a staged AVR can provide both viability and function with only mild edema formation.